This invention relates to turbo-generators in general and more particularly to a method for controlling a turbo-generator set including a generator, a turbine and a power control which delivers a control signal for control valves preceding and supplying steam to the turbine.
The customary method of controlling turbo-generator sets includes replacing the power control whose output signal acts on the control valves releasing the live steam, in the case of disturbances, such as load shedding or network short circuits, with the speed control required for starting the turbine. This cushions the speed increasing influence of these disturbances. In addition to the closing command of the speed control, a closing signal is fed directly into the hydraulic control system for a constant time by means of a load relay (German journal "VGB Kraftwerkstechnik 59" no. 6, June 1979, pp 467-472). It is a disadvantage of this method that, in the case of load shedding, a considerable speed acceleration is unavoidable and that, in the case of a network short circuit, after its correction, the reconnection of the power control takes place at a state of unbalance, so that power hunting of the turbo-generator set which may occur is usually further amplified.
It is an object of the present invention, in controlling turbo-generator sets of this general type, to avoid these disadvantages and to counteract the mentioned disturbances faster and more effectively.